PURIFICATION OF EXTRACELLULAR CHOLESTEROL OXIDASE WITH HIGH-ACTIVITY IN THE PRESENCE OF ORGANIC-SOLVENTS FROM PSEUDOMONAS SP. STRAIN ST-200

Authors
Citation
N. Doukyu et R. Aono, PURIFICATION OF EXTRACELLULAR CHOLESTEROL OXIDASE WITH HIGH-ACTIVITY IN THE PRESENCE OF ORGANIC-SOLVENTS FROM PSEUDOMONAS SP. STRAIN ST-200, Applied and environmental microbiology, 64(5), 1998, pp. 1929-1932
Citations number
17
Categorie Soggetti
Microbiology,"Biothechnology & Applied Migrobiology
ISSN journal
00992240
Volume
64
Issue
5
Year of publication
1998
Pages
1929 - 1932
Database
ISI
SICI code
0099-2240(1998)64:5<1929:POECOW>2.0.ZU;2-B
Abstract
Extracellular cholesterol oxidase of Pseudomonas sp. strain ST-200 was purified from the culture supernatant. This oxidase contained bound f lavin and was categorized as a 3 beta-hydroxysteroid oxidase, converti ng 3-hydroxyl groups to keto groups. The molecular mass was 60 kDa. Th e enzyme was stable at pH 4 to 11 and active at pH 5.0 to 8.5, showing optimal activity at pH 7 at 60 degrees C. The Michaelis constant of t he ST-200 cholesterol oxidase was lower than those of commercially ava ilable oxidases. The cholesterol oxidation rate was enhanced 3- to 3.5 -fold in the presence of organic solvents, with log P-ow values (parti tion coefficients of the organic solvent between n-octanol and water), in the range of 2.1 to 4.2, compared with that in the absence of orga nic solvents.